BL 4 inch naval gun Mk VII
, 1918 |origin= United Kingdom |type= Naval gun |is_ranged=yes |is_explosive= |is_artillery=yes |is_UK=yes |service=1908 - 1945 |used_by= United Kingdom |wars= |designer= |design_date= |manufacturer= |production_date= |number=600 |variants= |weight= (barrel & breech) |length= |part_length= bore (50.3 calibres)HANDBOOK for the 4" Mark VII. and VIII. B.L. Guns 1913 |width= |height= |crew= |cartridge= Common pointed, Common lyddite |caliber= |action= |rate= |velocity= 2852 ft/second firing a 31 lb 3 C.R.H. projectile, using 9 lb 5 oz 15 drams cordite MD size 16 propellant. HANDBOOK for the 4" Mark VII. and VIII. B.L. Guns 1913. |range= |max_range= at 15°Campbell, Warship Volume X, p. 53. |sights= |breech=Welin, Single-motion screw |recoil= |carriage= |elevation= |traverse= }} The 'BL 4-inch gun Mk VII'Mk VII = Mark 7. Britain used Roman numerals to denote Marks (models) of ordnance until after World War II. Mark VII indicates this was the seventh model of BL 4-inch gun. was a British high-velocity naval gun introduced in 1908 as an anti-torpedo boat gun in large ships, and in the main armament of smaller ships. It was also used as a defensive weapon on Defensively Equipped Merchant Ships (DEMS) during the Second World War. Naval history The guns armed the following warships : * s, laid down 1906 * s, laid down 1907 * scout cruisers, laid down 1907 * , laid down 1909 * battleships, laid down 1909 * s, laid down 1909 * s, laid down 1909 * s, laid down 1909 * ''Bristol''-class light cruisers, laid down 1909 * scout cruisers, laid down 1909 * scout cruisers, laid down 1910 * battleships, laid down 1911 , 1943]] The gun was succeeded in the "heavy" 4-inch class on new warships commissioned from 1914 onwards by the QF 4 inch Mk V. This new generation of warships were more heavily armed, and the BL Mk VII's role as secondary armament on capital ships and primary armament on cruisers was taken over by the BL 6 inch Mk VII and BL 6 inch Mk XII while the 4-inch calibre became the secondary armament on cruisers and primary armament on destroyers. In World War II many guns were used to arm merchant ships. World War I field gun service A battery of 4 guns mounted on field carriages was first deployed with the South African Heavy Artillery in the German South West Africa campaign in 1915 and returned to England in September. They were then deployed in the East African Campaign from February 1916 with 11th Heavy Battery (renumbered 15th Battery from April 1916) manned by the Royal Marine Artillery.Farndale 1988, page 318 Image gallery File:BL 4 inch Mk VII gun barrel diagram.jpg| Barrel dimensions File:BL 4 inch Mk VII Gun Breech Diagram.jpg| Breech mechanism File:BL 4 inch Mk VII Gun Percussion & Electric Locks Diagram.jpg| Percussion and electric locks File:BL 4 inch Mk VII gun on field carriage.jpg| Field carriage as depicted in 1913 manual Surviving examples ]] * [http://web.archive.org/web/20091027123448/http://www.geocities.com/kelburn.geo/4inchguns.html 2 Mk VII guns from HMS New Zealand] outside the Auckland War Memorial Museum See also * List of naval guns Weapons of comparable role, performance and era * 4"/50 caliber gun US equivalent Notes References * HANDBOOK for the 4" Mark VII. and VIII. B.L. Guns 1913 (Corrected to September 1913.) ADMIRALTY Gunnery Branch, G.8652/13 * * DiGiulian, Tony. British 4"/50 (10.2 cm) BL Mark VII * Farndale, General Sir Martin. History of the Royal Regiment of Artillery : Forgotten Fronts and the Home Base 1914-18. London:The Royal Artillery Institution, 1988 External links Category:Naval guns of the United Kingdom Category:World War I naval weapons of the United Kingdom Category:100 mm artillery